Sex Differences in the Neural Correlates of Openness: Most previous research on the neurological basis of personality has focused on traits related to Neuroticism and Extraversion, to the neglect of the other traits within the Five-Factor Model (FFM) of personality. Equally important within the FFM, the trait Openness to Experience captures individual differences in cognitive flexibility, need for variety, and depth of emotional experience. Although open individuals score high on neuropsychological tests that assess function of the dorsolateral prefrontal cortex (DL-PFC), there is no direct evidence for the association between Openness and activity in specific brain regions. Further, the sex differences in the neural activity often observed for cognitive traits may also apply to personality traits. In this research, we investigated sex differences in the resting-state neural correlates of Openness to Experience. Using resting-state PET from 100 older individuals (>55 years of age), we identified associations between Openness and resting-state regional cerebral blood flow (rCBF) that replicated across two assessments of the same sample, approximately two years apart. Higher Openness scores correlated positively with resting-state rCBF in the dorsolateral prefrontal cortex (DL-PFC), the anterior cingulate (ACC), and in the orbitofrontal cortex (OFC). These relations were both specific and common across the sexes: Openness correlated with regions of the brain related to working memory for women (DL-PFC), attention and reward for men (ACC), and emotional and reward processing for both sexes (OFC). It is striking that Openness correlated positively with brain regions linked to working memory and attention as these are the two executive functions crucial for the core characteristic of Openness to Experience cognitive flexibility. It is also notable that these relations were sex-specific;this divergence suggests that the two sexes rely on different neural pathways for the operations that define the trait Openness to Experience. The results challenge the implicit assumption that the same trait will rely on the same neural mechanisms across all who express it. In previous years, we noted the limitations in existing studies of personality stability and change, especially the need for longitudinal studies of ethnic minorities. We also suggested the need for future research in the community or epidemiological investigations to study the causes of the modest changes that occur in personality traits in adulthood. Our main objective was to assess the influence of job characteristics or aspects of the working environment captured by the Demand-Control Model of work stress as possible sources of non-normative personality changes in middle adulthood. Additionally we sought to examine the concurrent as well as the prospective relations in the dynamic transition between extrinsic and intrinsic career success and measures of the Five-Factor Model of Personality. Reciprocal Influences of Personality and Job Characteristics Across Middle Adulthood:There is a presumed reciprocal relation between experiences at work and personality: characteristics of the working environment are thought to contribute to personality development and, likewise, personality is thought to shape the daily realities of the job. Yet, few studies have measured both personality and the working environment at two points in time to explicitly test this reciprocal relation. To that end, we examined the concurrent (N = 722) and longitudinal (N = 297) relations between personality traits and occupational experiences across a ten-year period of middle adulthood in an economically-diverse community sample, The Baltimore ECA. We used a two-wave panel design to address their reciprocal change within the framework of the Five-Factor Model of personality and the Demand-Control Model of the working environment. Measured concurrently, participants high in Neuroticism reported less decision making latitude at work, whereas participants high in Extraversion, Openness, and Conscientiousness reported more latitude. Disagreeable participants were employed in physically demanding jobs and jobs with a hazardous working environment. Finally, those low in Extraversion and Conscientiousness also reported jobs with hazardous working conditions. Longitudinally, personality at baseline had the strongest relation with changes in the Decision Latitude dimension: Participants high in Neuroticism decreased in decision making latitude, whereas extraverted, open, and conscientious participants at baseline reported more decision making latitude at the 10-year follow-up. Agreeableness was unrelated to change in this dimension. Disagreeable participants did, however, report more physical demands on the job and introverted participants reported more hazardous working conditions. In contrast, none of the job characteristics predicted change in personality over this time interval. These findings suggest that as individuals progress through their careers in mid-life, they mold their everyday experiences on the job to fit their personality. Everyday working experiences, however, largely do not shape personality or strengthen corresponding aspects of the individuals personality. Our design offered two important advancements over previous research. First, the economically-diverse, middle-aged sample allowed us to examine the interplay between personality and job characteristics in individuals with established careers employed in a broad range of occupations;previous research has relied primarily on either young adults or select groups of adults. Second, we assessed both personality and job characteristics at two time points, which allowed us to test the influence of one variable on the other, controlling for their initial levels and concurrent relations. By measuring both personality and job characteristics at each time point, we had greater control over testing the hypothesized temporal relations. Our findings highlight the importance of traits for real-world consequences, but suggest that these consequences have a much smaller effect on subsequent personality development. Personality and Career Success Concurrent and Longitudinal Relations: In this research, we addressed the dynamic transaction between extrinsic (occupational prestige, income) and intrinsic (job satisfaction) career success and the Five-Factor Model of personality. Participants (N = 731) were drawn from the Baltimore ECA study. They completed a comprehensive measure of personality and reported their job title, annual income, and job satisfaction;a subset of these participants (n = 302) provided the same information approximately 10 years later. Measured concurrently, controlling for sex, ethnicity, age, and education, participants high in Neuroticism or low in Conscientiousness reported lower annual incomes and lower job satisfaction. Our longitudinal analyses revealed that, among younger participants, earning a higher income at baseline predicted decreases in Neuroticism across the 10 years between baseline and follow-up and higher levels of Extraversion predicted increases in income over this time period. The present findings implicate one aspect of the environment in personality development: those who earn higher incomes decrease on Neuroticism. It is of note that it is not how much one enjoys his job or the everyday realities of the working environment that contributes to personality development, but rather the material rewards of the job. Both personality and career success have been hypothesized to mutually influence each other across the lifespan. The current research suggests that this dynamic transaction may be limited to income and may only occur early in the career when both personality and careers are in flux.